CN114167432A

CN114167432A - Power supply unit, transmitting device comprising same and control method

Info

Publication number: CN114167432A
Application number: CN202010858924.0A
Authority: CN
Inventors: 路静静; 陈杰; 向少卿
Original assignee: Hesai Technology Co Ltd
Current assignee: Hesai Technology Co Ltd
Priority date: 2020-08-24
Filing date: 2020-08-24
Publication date: 2022-03-11

Abstract

The invention provides a power supply unit of a laser, comprising: a primary voltage source configured to output a primary voltage; a high voltage generating unit coupled to the primary voltage source, configured to input a primary voltage, generate an output voltage higher than the primary voltage, and output the output voltage through an output terminal; a capacitor unit coupled to an output terminal of the high voltage generating unit; the high voltage generating unit and the capacitor unit are configured to adjust the output voltage through charging and discharging matching.

Description

Power supply unit, transmitting device comprising same and control method

Technical Field

The present invention relates generally to the field of laser radar technology, and more particularly, to a power supply unit for a laser, a transmitter including the same, and a method for controlling light emission of a laser using the same.

Background

In a laser radar transmission system, a common anode is generally adopted to drive a laser. For example, as shown in fig. 1A, in a transmitting system of a laser radar in the prior art, a plurality of lasers LAS1 … lann share a power supply HV, HV is continuously supplied, a cathode of each laser is connected to a switching device (J1 … JN in the figure), and the light emission of the laser is determined by the gating of the switching device. Ideally, each laser is equipped with a discharge capacitor (shown as C1 … CN), and due to the size of the switching devices and capacitors in the prior art, the multiple lasers cannot be arranged more densely, so that the vertical resolution of the radar is limited.

Fig. 1B shows the power supply and the driving circuit of a single laser LAS1, the switching device used is GaN, and the specific working process is as follows: when the high-side switch is closed (turned on), the power supply HV charges the capacitor C, after a period of time, the high-side switch is turned off (the capacitor C cannot be energized, and the charging circuit of the capacitor C is turned off), and after the GaN switch tube is sufficiently opened by the driving signal of the GaN switch, a discharging circuit is formed among the capacitor C, the laser LAS1, the GaN switch and the ground, so that the laser LAS1 emits light.

FIG. 2A shows the relative arrangement of multiple lasers, GaN switches and capacitors on a PCB, and referring to FIG. 2A, because the GaN switches and capacitors are limited in size (the GaN switches and capacitors are relatively large, for example, in the actual packaging process, the discharge capacitor is selected according to the parameters of capacitance value and capacitance withstand voltage, etc., the capacitor can be selected according to the EIA standard, the capacitor has a size of 1000um 500um, and the packaging size is generally recommended to be 1400um 900um in consideration of the SMT (surface mount technology) process, and for the GaN switch, the withstand voltage and the same current capability are considered in selection, the minimum size that can be achieved by the prior art is about 680um, and the packaging is generally recommended to be 800um in consideration of the SMT process), the capacitors and the GaN switches can only be separately arranged on two sides of the lasers, and because one GaN switch is required to drive one laser (i.e., the ratio of the number of the lasers to the number of the GaN switches is 1: 680um 1) The GaN switches themselves are also arranged in two rows and staggered.

As shown in fig. 2B after the arrangement of fig. 2A is simplified, referring to fig. 2A and fig. 2B, it can be seen that the distance between the laser LAS2 and its corresponding GaN switch is larger than the distance between the laser LAS1 and its corresponding driven GaN switch. The staggered placement of the GaN switches results in different discharge loop lengths between the two lasers (e.g., LAS1 and LAS2), which may result in different light emitting powers of the two lasers. And the GaN switch can not be well attached to the laser, and certain influence is caused on the response speed of the laser.

The laser radars for the unmanned vehicles, the logistics trolleys and the sweeping robots are generally multi-line radars, which means that a transmitting system is provided with a plurality of lasers, and if the lasers are arranged according to the relative relationship shown in fig. 2A and fig. 2B, the distance between each laser and a corresponding GaN switch is relatively inconsistent, so that the detection accuracy and other parameters of each channel or wire harness are different, the detection consistency is not facilitated, and the overall performance of the laser radars is influenced.

Furthermore, as shown in fig. 1A, the power supply source HV is supplied to the line at a fixed value (for example, HV ═ 20V), and cannot be adjusted quickly. This is because, after the power supply is adjusted too fast, various capacitive and inductive effects accumulate on the line and cannot be changed as desired. In addition, the current high voltage supply usually adopts a DC-DC power supply or an ldo (low drop out regulator) mode, and the switching speed is slow, so that the light intensity of the laser cannot be adjusted quickly. However, if the same fixed light intensity is used for detection in multiple ends of external environment changes faced by the laser radar, the detector is easily saturated or cannot detect signals due to the reflectivity difference of the external target, and the requirements of various scenes cannot be met. Moreover, each wire harness detection index of the radar, such as detection distance, may also be different, and there is a need for adjustment.

The statements in this background section merely represent techniques known to the public and are not, of course, representative of the prior art.

Disclosure of Invention

In order to solve the problem that the adjustment speed of the bus voltage in the prior art is slow, and the bus voltage cannot be changed as expected, that is, the bus voltage cannot be changed at a high speed, so that the light intensity of the laser cannot be adjusted quickly, the invention also provides a power supply unit of the laser, which comprises:

a primary voltage source configured to output a primary voltage;

a high voltage generating unit coupled to the primary voltage source, configured to input a primary voltage, generate an output voltage higher than the primary voltage, and output the output voltage through an output terminal;

a capacitor unit coupled to an output terminal of the high voltage generating unit;

the high voltage generating unit and the capacitor unit are configured to adjust the output voltage through charging and discharging matching.

According to an aspect of the present invention, wherein the high voltage generating unit includes:

a first inductor having a first terminal coupled to the primary voltage source and configured to input electrical energy from the primary voltage source;

a first switch tube, a first end of which is coupled to a second end of the first inductor, and a second end of which is grounded, and configured to enable the primary voltage source and the first inductor to form a charging loop when being conducted, so as to charge the first inductor;

and a second switch tube, a first end of which is coupled to the second end of the first inductor, and a second end of which is coupled to the capacitor unit, and is used as an output end of the high voltage generation unit.

According to an aspect of the invention, the power supply unit further comprises a reset switch tube connected across the primary voltage source and the capacitor unit and configured to pull the output voltage back to the primary voltage.

According to an aspect of the invention, the first switch tube, the second switch tube and the reset switch tube comprise one or more of a GaN switch and a CMOS switch tube.

The invention also provides a laser radar transmitting device, comprising:

a plurality of power supply units as described above configured to convert the primary voltage to a high voltage output;

a laser unit including a plurality of lasers, wherein one end of each laser is connected to an output terminal of one of the power supply units, so that at least two lasers are connected to output terminals of different power supply units;

and the cathode of the partial laser which does not share the high voltage is connected with one of the switching devices, and the switching device is configured to be capable of switching on and off a current loop formed by one of the high voltages, the laser connected with the switching device and the ground.

The present invention also provides a control unit for controlling the power supply unit as described above, wherein the high voltage generating unit includes a first switching tube, a second switching tube and a reset switching tube, the control unit includes:

and generating a voltage control signal according to a light emitting time sequence of the laser, and outputting the voltage control signal to control electrodes of the first switch tube, the second switch tube and the reset switch tube respectively so as to control the high-voltage generation unit to output an output voltage higher than the primary voltage and control the capacitor unit and the high-voltage generation unit to adjust the output voltage through charge-discharge matching.

The present invention also provides a method of controlling light emission of a laser using the power supply unit as described above, comprising:

outputting a primary voltage by the primary voltage source;

generating an output voltage higher than the primary voltage by the high voltage generating unit;

the output voltage is adjusted through the charging and discharging of the capacitor unit and the high-voltage generating unit.

According to an aspect of the present invention, wherein the high voltage generating unit includes: a first inductor having a first terminal coupled to the primary voltage source, a first switch coupled to a second terminal of the first inductor and a second terminal coupled to ground, a second switch coupled to the second terminal of the first inductor and a second terminal coupled to the capacitor unit, the method further comprising:

inputting electrical energy from the primary voltage source through the first inductor;

when the first switch tube is closed and the second switch tube is opened, the primary voltage source and the first inductor form a charging loop, and the primary voltage source charges the first inductor;

the first switch tube is opened, the second switch tube is closed, the primary voltage source and the first inductor form a discharge loop, and the capacitor unit is charged through the primary voltage source and the first inductor, so that the output voltage is higher than the primary voltage.

According to one aspect of the invention, the method further comprises:

the capacitor unit is discharged by the first switch tube being opened and the second switch tube being closed, and the first inductor inputs electric energy from the capacitor unit to reduce the output voltage.

According to an aspect of the invention, wherein the power supply unit further comprises a reset switch tube connected across the primary voltage source and the capacitor unit, the method further comprises:

and the output voltage is pulled back to the primary voltage through the reset switch tube.

The preferred embodiment of the invention provides a power supply unit comprising an LC resonance circuit, and due to the characteristics of the LC resonance circuit, the speed of charging and discharging a mounted capacitor by the power supply unit is greatly improved, compared with the scheme of a feedback circuit used in the prior art, the speed is improved by thousands of times, and then the light intensity of a plurality of lasers of a laser radar can be adjusted more quickly relative to the speed so as to be matched with the condition of an external obstacle or a use scene, and thus the accuracy of point cloud detection is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1A schematically shows a laser radar transmitting device under a single bus power supply system;

FIG. 1B schematically shows a circuit configuration for driving a laser with a GaN switching device;

FIG. 2A schematically illustrates the arrangement of components on a PCB board under a single bus power system;

FIG. 2B schematically illustrates the arrangement of components on a PCB board under a single bus power system;

FIG. 3 schematically illustrates a transmitting device according to a preferred embodiment of the present invention;

FIG. 4A schematically illustrates a transmitting device in accordance with a preferred embodiment of the present invention;

fig. 4B schematically shows a specific implementation structure of a 3-bus transmission apparatus according to an embodiment of the present invention;

FIG. 4C shows the output voltage waveform of the preferred embodiment shown in FIG. 4B;

fig. 4D schematically shows a specific implementation structure of a 2-bus transmitting device according to an embodiment of the present invention;

FIG. 4E illustrates the output voltage waveform of the preferred embodiment shown in FIG. 4D;

FIG. 5 schematically illustrates the arrangement of components on a PCB board under a two bus power system in accordance with a preferred embodiment of the present invention;

FIG. 6 schematically illustrates the routing of components on a PCB board under a two-bus power system according to a preferred embodiment of the present invention;

FIG. 7 schematically illustrates the arrangement of components on a PCB board under a four bus power system in accordance with a preferred embodiment of the present invention;

fig. 8 schematically shows a power supply unit of a laser according to a preferred embodiment of the invention;

fig. 9A schematically shows a specific implementation structure of a power supply unit;

FIG. 9B schematically shows a simulation curve of the operation of the power supply unit of FIG. 9A;

fig. 9C schematically shows a specific implementation structure of a power supply unit according to a preferred embodiment of the present invention;

fig. 10A schematically illustrates a first charging process of the high voltage generating unit according to a preferred embodiment of the present invention;

fig. 10B shows a variation curve of the first inductance, the output voltage of the power supply unit according to a preferred embodiment of the present invention;

fig. 11A schematically illustrates a second charging process of the high voltage generating unit according to a preferred embodiment of the present invention;

fig. 11B shows a variation curve of the first inductance, the output voltage of the power supply unit according to a preferred embodiment of the present invention;

fig. 12A schematically illustrates a first discharge process of the high voltage generating unit according to a preferred embodiment of the present invention;

fig. 12B shows a variation curve of the first inductance, the output voltage of the power supply unit according to a preferred embodiment of the present invention;

fig. 13A schematically illustrates a second discharge process of the high voltage generating unit according to a preferred embodiment of the present invention;

fig. 13B shows a variation curve of the first inductance, the output voltage of the power supply unit according to a preferred embodiment of the present invention;

fig. 14A schematically illustrates a reset process of the high voltage generating unit according to a preferred embodiment of the present invention;

fig. 14B shows a variation curve of the first inductance, the output voltage of the power supply unit according to a preferred embodiment of the present invention;

fig. 15 illustrates a method of controlling laser light emission using a power supply unit according to a preferred embodiment of the present invention;

FIG. 16 schematically illustrates a lidar in accordance with a preferred embodiment of the present invention;

fig. 17 schematically shows an application scenario of the lidar according to a preferred embodiment of the present invention.

Detailed Description

In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", may explicitly or implicitly include one or more of the described features. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection, either mechanically, electrically, or in communication with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly above and obliquely above the second feature, or simply meaning that the first feature is at a lesser level than the second feature.

The following disclosure provides many different embodiments or examples for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, such repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize applications of other processes and/or uses of other materials.

The embodiments of the present invention will be described in conjunction with the accompanying drawings, and it should be understood that the embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not intended to limit the present invention.

First aspect

It is reasonable to speculate that due to the upgrading of laser radar products, the radar tends to be designed in a chip mode in consideration of the aspects of difficulty, cost, miniaturization and the like of assembly. The laser that future laser radar adopted can encapsulate as a chip, and the drive circuit for driving the laser also can encapsulate as the chip, and because the restriction of current technology, the laser is common cathode mostly, then the negative pole of a plurality of lasers of encapsulation is made together jointly in the chip of laser, and ground connection (GND) afterwards, then between the negative pole of every laser and GND, can't set up other device. If the driving circuit is arranged between the cathode of the laser and the GND and the cathodes of the lasers are connected, the lasers need to share one switching device for input driving, and if the lasers need to be gated independently relative to each other (for example, the laser 1 can be gated independently to enable the laser 1 to emit light, and the laser 2 does not emit light at this time), or the laser 2 can be gated independently to enable the laser 2 to emit light, and the laser 1 does not emit light at this time, but the laser 1 and the laser 2 do not need to be gated simultaneously), a scheme can be adopted to drive the lasers by arranging the switching device at the anode of the lasers, but the scheme needs to adopt a high-side switch, and the regulation and control need to be realized, and the scheme is relatively complex. Based on the objective of realizing independent gating of multiple lasers and the motivation of saving GaN, the present application proposes a technical solution that multiple lasers are respectively provided with power supplies instead of sharing the power supplies, and the solution of the present application will be described and illustrated in detail below with reference to fig. 3-17.

According to a preferred embodiment of the present invention, as shown in fig. 3, the present invention provides a transmitting apparatus 10 usable with a lidar, including a plurality of power supply units 11, such as the power supply unit 11-1, the power supply unit 11-2 … power supply unit 11-N shown in the drawing, a laser unit 12, and at least one switching device 13.

The plurality of power supply units 11 are configured to convert the primary voltage into a high voltage output (e.g., HV1, HV2 … HVN, hereinafter referred to as a high voltage HVx, which is a voltage higher than the primary voltage, in the figures, for any one of the high voltages HV1, HV2 … HVN), and at least two power supply units 11 do not simultaneously output the high voltage, for example, the power supply unit 11-1 may output the high voltage HV1 at time t1, and the power supply unit 11-2 may output the high voltage HV2 at time t2, where t1 ≠ t 2.

The laser unit 12 includes a plurality of lasers 121, such as laser 121-1, laser 121-2 … laser 121-N as shown. The laser unit 12 may be a one-dimensional laser or a two-dimensional laser array, and accordingly, the laser 121-x (including the laser 121-1 and the laser 121-2 … laser 121-N) shown in fig. 3 may be 1 laser, 1 column laser, or 1 row laser. In connection with this, the anode of each laser 121-x is connected to the output of the power supply unit 11, wherein at least two lasers 121-x may be connected to different power supply units 11, for example, the anode of the laser 121-1 is connected to the output of the power supply unit 11-1, and the anode of the laser 121-2 is connected to the output of the power supply unit 11-2. At least one switch device 13, the cathodes of the partial lasers (such as the laser 121-1 and the laser 121-2 … shown in the figure) not sharing the high voltage are connected to the same switch device 13, the switch device 13 is configured to switch on and off a discharge loop formed by one high voltage HVx output correspondingly, the laser connected with the switch device and the Ground (GND), for example, when the power supply unit 11-1 outputs the high voltage HV1 at the time of t1, if the switch device 13 is also switched on at the time of t1, the discharge loop formed by the high voltage HV1, the laser 121-1 connected with the switch device and the ground can be switched on.

By adopting the scheme provided by the invention, even though a plurality of lasers share the same switching device 13, the partial lasers 121-x in the laser unit 12 (the laser unit 12 comprises the laser 121-1 and the laser 121-2 … laser 121-N) can be individually gated one by one through at least two power supply units 11 (including the power supply unit 11-1 and the power supply unit 11-2 …) which output high voltages at different times, and the lasers 121 in the laser unit 12 shown in fig. 3 are all 1 laser as is easily understood by those skilled in the art. In another embodiment, the laser 121 may also be a column of multiple lasers or a row of multiple lasers, so that the defect of insufficient light intensity of 1 laser can be overcome, and the distance measurement capability of the laser radar is further improved. In addition, it is within the scope of the present invention to control the partial lasers 121 in the laser unit 12 to detect with different light emission intensities by different power supply units 11 outputting different high voltages (e.g., HV1 ═ 20V, HV2 ═ 40V).

For convenience of understanding, in the present invention, each component constituting the power supply unit and lines connecting the corresponding components are collectively referred to as a voltage BUS, and a plurality of voltage Buses (BUS) connect each functional component of the power supply unit 11 together to form an HVBUS. Specifically, 1 Vbase +1 boost circuits are combined together to form a power supply unit 11, and the output of the power supply unit 11 is used for supplying high voltage HV1 for the laser radar, so that 1 voltage bus HVBUS is formed; the combination of 1 Vbase and 1 further boost circuit constitutes a further power supply unit 11, the output of this power supply 11 being, for the radar, the supply of high voltage HV2, thus constituting the further 1 voltage bus HVBUS. Fig. 4A shows an embodiment of a two-bus power supply system provided by the present invention, wherein two buses share a primary voltage source 112, and specifically, the transmitting device 10 includes a plurality of voltage buses 14 corresponding to a plurality of power supply units 11, wherein the input end of the voltage bus 14 inputs a primary voltage (VBASE shown in the figure), the output end outputs a voltage higher than the primary voltage (HV 1, HV2 in the figure), and each laser 121-x is connected to the output end of the corresponding power supply unit 11 through one of the voltage buses 14.

It will be readily understood by those skilled in the art that although fig. 4A illustrates a two-bus case, it is within the scope of the present invention that the transmitting device 10 includes multiple voltage buses 14 outputting voltages HV1, HV2 … HVN, respectively, that are higher than the primary Voltage (VBASE), i.e., HVx > VBASE, and that the multiple voltage buses 14 may not share the primary voltage source 112.

According to a preferred embodiment of the present invention, as shown in fig. 4A, the power supply unit 11 of the transmitting device 10 includes a capacitor unit 111 connected to the voltage bus 14, configured to be charged through the voltage bus 14, and to discharge one or more lasers 121-x connected to the voltage bus 14 and gated by the switching device 13 when the switching device 13 is turned on, so as to drive the one or more lasers 121-x to emit light.

According to a preferred embodiment of the present invention, as shown in fig. 4A, the power supply unit 11 further includes a primary voltage source 112 and a high voltage generating unit 113. The primary voltage source 112 is configured to output a primary Voltage (VBASE). The high voltage generating unit 113 is connected to a primary voltage source 112, the primary voltage source 112 is adapted to input a primary Voltage (VBASE) to the high voltage generating unit 113, and the high voltage generating unit 113 is configured to generate a voltage HVx higher than the primary Voltage (VBASE).

To facilitate a better understanding and implementation of the present invention by those skilled in the art, fig. 9C shows a voltage bus circuit, fig. 4B shows a 3-voltage bus laser circuit, and fig. 4D shows a 2-voltage bus laser circuit. Referring to fig. 4B, an inductor Lx (including an inductor L1, an inductor L2, and an inductor L3), a gate signal (including a gate1, a gate2, and a gate3), a switching tube Mx (including a switching tube M1, a switching tube M2, and a switching tube M3), and a diode Dx (including a diode D1, a diode D2, and a diode D3) form an energy storage circuit, a high-side tube Px (including a high-side tube P1, a high-side tube P2, and a high-side tube P3) and a high-side tube driver (including a driver 1, a driver 2, and a driver 3) form a gating circuit, and LD1-Ldx (including LD1, LD2, and LD3) and a trigger signal form a laser circuit. In addition, the diodes D11, D21 and D31 are used to protect the respective parallel-connected switching tubes, for example, the diode D11 protects the M1. The energy storage circuit 1 includes an inductor L1, a gate1, a switch tube M1, and a diode D1, the gating circuit 1 includes a high-side tube P1 and a driver 1, and the specific configurations of the other energy storage circuits x and the gating circuit x can be analogized, which is not described in detail herein.

The approximate operation of the laser to emit light is as follows: the energy storage circuit is used for receiving input primary voltage VBase and storing electric energy, the gating circuit is conducted, the energy storage inductor can charge the boosting capacitor C, and high voltage is built on the boosting capacitor C. Usually the input voltage is not very high, e.g. 5V or 12V, and cannot be used directly to drive the laser, requiring boosting. The high voltage built up on the boost capacitor C may be significantly higher than the input voltage VBase, e.g. 60V, and may thus be used to drive the laser LD. After the high voltage build-up is complete, the boost capacitor C may drive the laser LDx to emit a laser beam. The 3 HV buses share 1 primary voltage source VBase, the 3 lasers LD share 1 driving device S3, the 3 HV buses HV1, HV2 and HV3 do not output at the same time, and at a certain time, only one of the HV1, HV2 and HV3 outputs, so that the output of the capacitor C, HV, S3 and the discharge circuit of the ground are gated (it can be understood that a charging circuit is a relative concept for a certain pass circuit, specifically a charging circuit, and a discharge circuit is a relative concept for the capacitor C), and the laser LD connected to the pass circuit HV is driven to emit light. The laser LD may be various types of lasers, such as a vertical cavity surface emitting laser VCSEL, or an edge emitting laser EEL, and the scope of the present invention is not limited by the type of laser.

Referring to fig. 4B, the specific working of the specific tank circuit, gating circuit and laser circuit with each other will be described by taking the tank circuit 1, gating circuit 1 and LD1 as an example. The tank circuit 1 includes an inductor L1, a diode D1 connected to the inductor L1, and a switch M1. The inductor L1 has one end connected to the input voltage VIN (typically small, e.g., 5V), and the other end connected to the diode D1 and the switch M1.

If the output HV1 is selected at a certain time, the closed switch M1 may be equivalent to a short circuit in the circuit by controlling the switch M1 to be closed through the gate1 during the energy storage phase, so that the current generated by the input voltage VIN flows through the inductor L1 and is grounded through the switch M1. As the inductor current increases, electrical energy is stored in inductor L1.

When the energy storage phase is completed, the switch M1 is turned off, the P1 is gated by the high-side driver in the gating circuit 1, and at this time, because of the current holding characteristic of the inductor L1, the current flowing through the inductor L1 does not immediately become zero, but slowly changes from the current value at the time of completion of charging to zero, and in this process, because the switch M1 is already turned off and the P1 is turned on, the inductor L charges the boost capacitor C1, so that the voltage across the boost capacitor C1 rises.

After a high voltage (for example, 60V) is already established on the boost capacitor C1, if the driving switch S3 in the selected laser circuit is turned on (can be turned on or off by trigger3 signal), the capacitor C1 cannot discharge through the diode D1 due to the unidirectional conductivity of the diode D1, and can only discharge through the loop of the laser LD1 and the switch S3, so that a current flows through the laser LD1, and the capacitor C1 drives the laser LD1 to emit light.

At the next moment, if the laser LD2 is driven to emit light, the energy storage circuit 2, the gating circuit 2 and the LD2 can repeat the working process of the energy storage circuit 1, the gating circuit 1 and the LD 1; at the next moment, if the laser LD3 is driven to emit light, the energy storage circuit 3, the gating circuit 3, and the LD3 may repeat the working processes of the energy storage circuit 1, the gating circuit 1, and the LD1, which is not described herein again.

FIG. 4C provides a simulation of the operation of the laser circuit shown in FIG. 4B, with time t on the horizontal axis and voltage V on the vertical axis, curve 401 representing the change in HV1, curve 402 representing the change in HV2, and curve 403 representing the change in HV 3. As can be seen, HV1 has an output during the time period of 0.5 μ s-3.5 μ s, HV2 has an output during the time period of 5.5 μ s-8.5 μ s, HV3 has an output during the time period of 10.5 μ s-13.5 μ s, and the outputs of HV1, HV2, and HV3 do not coincide and can gate the emission of one or more lasers connected to the voltage buses of the outputs HV1, HV2, and HV3, respectively.

To facilitate understanding of the present invention by those skilled in the art, fig. 4D shows a 1-bus 2-bus laser circuit scheme, and another embodiment of the present application is described with reference to fig. 4D and fig. 9C, as shown in the figure, the high voltage generating unit 113 includes a first inductor 1131, a first switch tube 1132 and a second switch tube 1133. The first terminal of the first inductor 1131 is connected to the primary voltage source 112 and is configured to input electrical energy from the primary voltage source 112. The first switch tube 1132 has a first end connected to the second end of the first inductor 1131, and a second end grounded, and is configured to make the primary voltage source 112 and the first inductor 1131 form a charging loop to charge the first inductor 1131 when the first switch tube is conducted. The first end of the second switch tube 1133 is connected to the second end of the first inductor 1131, and the second end is connected to the capacitor unit 111, and is configured to enable the primary voltage source 112 and the first inductor 1131 to form a discharge loop when conducting, so as to charge the capacitor unit 111. In addition, the diodes D1 are all used to protect the respective parallel-connected switching tubes, such as the diode D1 protects the switching tube 1132. The diode D2 is used to accelerate conduction and power supply, and the diode D2 accelerates the supply of HV 2. In contrast to the scheme shown in fig. 4B, the capacitance of the capacitor C that can be used to charge the laser is relatively larger in this embodiment.

According to a preferred embodiment of the present invention, as shown in fig. 4D, the two voltage buses output high voltages HV1 and HV2, respectively, each bus has a certain number of lasers 121 mounted thereon (specifically, as shown in fig. 4D, a voltage bus with an output voltage HV1 has 121-1, 121-3 and 121-5 mounted thereon, and a voltage bus with an output voltage HV2 has 121-2, 121-4 and 121-6 mounted thereon), two adjacent lasers share a GaN switch as a driver (specifically, as shown in fig. 4D, the lasers 121-1 and 121-2 share the GaN switch 13-1, the lasers 121-3 and 121-4 share the GaN switch 13-2, and the lasers 121-5 and 121-6 share the GaN switch 13-3), the driver signal DRV1 is shown for driving the GaN switch 13-1, deciding the on-off and the on-off duration of the GaN switch 13-1; similarly, the driving signal DRV2 is shown to drive the GaN switch 13-2, so as to determine the on/off state and the on/off duration of the GaN switch 13-2; the DRV3 is used for driving the GaN switch 13-3 and deciding the on-off and the on-off duration of the GaN switch 13-2.

As shown in fig. 4D and 9C, the high voltage generating unit 113 of the power supply unit 11 has three control signals, which are the low side driving DRVL _ HV1 (driving the first switch tube 1132), the high side driving DRVH _ HV1 (driving the second switch tube 1133), and the reset driving DRVRST _ HV1 (driving the reset switch tube 1134). The control signal inputs of the low-side driver DRVL _ HV1, the high-side driver DRVH _ HV1, and the reset driver DRVRST _ HV1 together form a voltage control terminal of the power supply unit 11, which receives an external voltage control signal to control the output voltage of the power supply unit 11 according to a preferred embodiment of the present invention.

According to a preferred embodiment of the present invention, as shown in fig. 4A, each of the switching devices 13 includes a control terminal (input terminals of the DRV1, DRV2, DRV3 driving signals shown in the figure), a first terminal and a second terminal, the control terminal is configured to receive the driving signals to control the on/off between the first terminal and the second terminal, the first terminal is connected to the cathode of one or more lasers 121 gated by the switching device, the second terminal is connected to ground, and the voltage control signal and the driving signals cooperate to control the lasers 121 to emit light. Preferably, the switching device 13 includes one or more of a GaN switch, a CMOS switch tube.

Fig. 4E provides a simulation of the operation of the laser circuit shown in fig. 4D, with time t on the horizontal axis, voltage V on the vertical axis, a relatively thin curve 404 representing the change in HV1, and a relatively thick curve 405 representing the change in HV 2. as can be seen from the figure, HV1 has an output during the period of 0.5 μ s to 3.5 μ s, HV2 has an output during the period of 5.5 μ s to 8.5 μ s, and the output times of both HV1 and HV2 do not coincide, and one or more lasers connected to the voltage bus outputting HV1 and HV2, respectively, may be strobed to emit light.

The present invention also provides, according to a preferred embodiment of the present invention, a method of controlling light emission of the emission device 10 as described above (as shown in fig. 4A), which may include:

in step S201, one power supply unit 11 is controlled to output a high voltage;

in step S202, the current loop of a part of the lasers 121 is controlled to be turned on by the switching device 13, so that the lasers 121 connected to the power supply unit 11 emit light under the action of a high voltage.

According to a preferred embodiment of the present invention, the transmitting apparatus 10 further includes a plurality of voltage buses 14 corresponding to the plurality of power supply units 11, each voltage bus 14 is connected to each component on the corresponding power supply unit 11, an input end of the voltage bus 14 inputs a primary voltage, an output end of the voltage bus 14 outputs a voltage higher than the primary voltage, each laser 121 is connected to an output end of the corresponding power supply unit 11 through one of the voltage buses 14, the power supply unit 11 includes a capacitor unit 111 connected to the voltage bus 14, and the control method further includes:

the capacitor unit 111 is charged through the voltage bus 14, and the corresponding laser 121 connected to the same voltage bus 14 is discharged through the capacitor unit 111 to drive the corresponding laser 121 to emit light.

According to a preferred embodiment of the present invention, wherein the power supply unit 11 further comprises a primary voltage source 112, a high voltage generating unit 113, the control method further comprises:

outputting a primary voltage by a primary voltage source 112;

a voltage higher than the primary voltage is generated by the high voltage generating unit 113 and is output through the voltage bus 14.

According to a preferred embodiment of the present invention, wherein the high voltage generating unit 113 includes: a first inductor 1131, a first terminal of which is connected to the primary voltage source 112, a first switch 1132, a first terminal of which is connected to the second terminal of the first inductor 1131, and a second terminal of which is grounded, and a second switch 1133, a first terminal of which is connected to the second terminal of the first inductor 1131, and a second terminal of which is connected to the capacitor unit 111, the control method further includes:

inputting electrical energy from the primary voltage source 112 through the first inductor 1131;

the first switch tube 1132 is turned on, so that the primary voltage source 112 and the first inductor 1131 form a charging loop to charge the first inductor 1131;

by turning on the second switching tube 1133, the primary voltage source 112 and the first inductor 1131 form a discharge loop to charge the capacitor unit 111.

According to a preferred embodiment of the present invention, wherein the power supply unit 11 further comprises a voltage control terminal, the control method further comprises:

the voltage control terminal receives a voltage control signal to control the output voltage of the power supply unit 11.

According to a preferred embodiment of the present invention, each of the switching devices 13 includes a control terminal, a first terminal and a second terminal, the control terminal is configured to receive a driving signal to control the on/off between the first terminal and the second terminal, the first terminal is connected to the cathode of the laser which is gated by the first terminal, the second terminal is grounded, the control method further includes:

the voltage control signal and the driving signal are matched to control one or more lasers corresponding to the voltage control signal to emit light.

The present invention provides a method of arranging the transmitting device 10 as described above on a PCB: as shown in fig. 5, the plurality of lasers 121 are arranged in a single column, and the GaN switching devices corresponding to adjacent lasers may be arranged on two sides, as shown in the figure: lasers 121-1 and 121-2 correspond to GaN switch 13-1 and lasers 121-3 and 121-4 correspond to GaN switch 13-2. Lasers 121-0 and 121-1 are supplied with high voltage HV3 through capacitor 111-3, lasers 121-2 and 121-3 are supplied with high voltage HV1 through capacitor 111-1, and laser 121-4 is supplied with high voltage HV2 through capacitor 111-2, wherein high voltages HV1, HV2 and HV3 may be supplied non-simultaneously, i.e., at different times, so that individual gating control may be performed for any of the plurality of lasers 121. The ratio of the number of lasers to the number of GaN switching devices is 2: 1, it is equivalent to two lasers share one GaN switching device, and the GaN switching device is used for driving to emit light. This is easily achieved with the transmitting device of the present invention in a number of the preferred embodiments described above. The switching devices are arranged on two sides of the single-column laser, so that the distances from the multiple lasers to the switching devices for gating the multiple lasers are approximately equal, inconsistency of test parameters is avoided, and the consistency of all detection channels is good. Compared with the layout (as shown in fig. 2A and fig. 2B) of driving a laser by a GaN switching device, the discharge loop lengths are substantially equal, and the emission power of the laser is relatively uniform.

As shown in fig. 6, the present invention also provides another method of arranging the transmitting device 10 as described above on a PCB board: multiple lasers 121 are arranged in a single column with the GaN switching devices and capacitors C being arranged on the same side of the column. The wiring is divided into three layers, wherein the first layer is grounded and is connected with the GaN switch and the capacitor; the second layer is connected with the GaN switch device and the lasers, the third layer is connected with all capacitors, the capacitor units mounted on the voltage bus of the output voltage HV1 are connected with the corresponding lasers through the first layer of wires, the capacitor units mounted on the voltage bus of the output voltage HV2 are connected with the corresponding lasers through the second layer of wires, and due to the fact that the number of the GaN devices is smaller than that of the lasers, the distance from each laser to the GaN switch device driving the laser can be equal through the wiring mode, discharging loops of each laser are approximately equal, and difference of emission power cannot occur.

According to a preferred embodiment of the present invention, as shown in fig. 7, a method for arranging the transmitting device 10 of the 4-bus power supply system on the PCB board comprises: two columns of lasers are staggered, lasers 121-1, 121-2, 121-3 and 121-4 are respectively connected to four different power supply units (as shown in the figure, the output voltages of the four power supply units are HV1, HV2, HV3 and HV4 respectively), and the four lasers 121-1, 121-2, 121-3 and 121-4 share one GaN switch 13-1, so that the number of GaN switch devices is saved. The GaN switch 13-1 is connected with the lasers 121-1 and 121-3 through wiring on the PCB, and the connected lasers 121-2 and 121-4 are connected through wiring on the back of the PCB, so that the distances from the four lasers 121-1, 121-2, 121-3 and 121-4 to the GaN switch 13-1 for driving the lasers are approximately equal, the discharge loops of the lasers are equal, and the emission powers of the lasers are consistent. And the two rows of lasers are arranged in a staggered manner, so that the placement density of the lasers can be doubled, and the vertical angle resolution of the laser radar can be doubled.

The preferred embodiment arranges all the GaN switch devices on one side, each corresponding to multiple lasers, not only to ensure the consistency of the multiple lasers with their corresponding GaN switch devices, but also to make more room for arrangement because the GaN switch 13-1 is spaced further away from the GaN switch 13-2 as shown in the figure between two GaN switch devices. As shown in fig. 7, the four lasers 121-1, 121-2, 121-3 and 121-4 respectively correspond to different capacitors 111-1, 111-4, 111-2 and 111-5, and each laser, its corresponding capacitor and GaN switch device together form a power-on loop, so that the four lasers can emit light at a certain timing.

According to a preferred embodiment of the present invention, as shown in fig. 16, the present invention further provides a laser radar 20, which includes the transmitting device 10, the receiving device 21 and the control device 22, wherein: the emitting device 10 is adapted to drive the laser to emit the detection laser beam according to a certain timing sequence under the control of the control device 22. The receiving means 21 are adapted to receive echoes reflected back via external obstacles with respect to the radar. The control device 22 is adapted to generate voltage control signals (such as DRVH _ HV1, DRVL _ HV1 and DRVRST _ HV1 shown in fig. 4D) according to the detection requirement of the radar, control the output voltage of the power supply unit, and generate driving signals (such as DRV1, DRV2 and DRV3 shown in fig. 4A) to gate part of lasers to emit light; and is adapted to process the echo received by the receiving means 21 and to calculate the distance and/or reflectivity of the radar from the external obstacle from the echo signal.

According to a preferred embodiment of the present invention, fig. 17 shows an application scenario of the present invention, a laser radar 20 is mounted on an unmanned vehicle, a transmitting device 10 in the laser radar 20 outputs voltages at different times through different power supply units under the control of a control device 22, respectively gates some lasers to emit probe beams, a receiving device 21 receives echoes of the probe beams reflected by external obstacles, and then the distance and/or reflectivity between the external obstacles and the laser radar (the unmanned vehicle) is calculated according to the echo signals through the processing of the control device 22. Wherein the control unit 22 controls the output voltages of the plurality of power supply units of the transmitting device 10 by generating voltage control signals, and gates some of the lasers to emit light by generating driving signals.

The invention provides a laser radar transmitting device and a control method thereof.A plurality of power supply units are used for respectively gating lasers connected with the power supply units to emit light, a plurality of lasers with non-shared voltage can share a GaN switch device, so that one or a certain row or a certain column of lasers can be gated independently one by one, the cost and the volume of a transmitting end are saved, the size of the GaN switch device is not limited to the vertical angular resolution of the laser radar any more, and the GaN switch device can be respectively arranged at two ends of the plurality of lasers or adopts a wiring mode of routing at the back of a PCB (printed circuit board), so that the transmitting power of the plurality of lasers is consistent, the plurality of lasers are arranged in a staggered mode, and the angular resolution in the vertical direction is increased.

Second aspect of the invention

In order to achieve a fast regulation of the voltage of the power supply HV, a fast boost from the primary voltage, and a fast regulation of the output voltage for fast regulation of the light intensity of the laser, as shown in fig. 9C, the invention also provides a power supply unit 11 for a laser, comprising: a capacitor unit 111, a primary voltage source 112, and a high voltage generating unit 113. The primary voltage source 112 is configured to output a primary voltage. The high voltage generating unit 113 is coupled to the primary voltage source 112, configured to input a primary voltage, generate an output voltage higher than the primary voltage, and output the high voltage through an output terminal. The capacitance unit 111 is coupled to an output terminal of the high voltage generating unit 113. The capacitor unit 111 and the high voltage generating unit 113 are configured to adjust the output voltage by charging and discharging.

Fig. 9C shows a specific implementation structure of the power supply unit 11, according to a preferred embodiment of the present invention, the primary voltage source 112 outputs a primary voltage (VBASE 1 shown in the figure), the high voltage generating unit 113 is coupled to the primary voltage source 112 to convert the primary voltage VBASE1 into a high voltage output (HV 1 shown in the figure), and the capacitor unit 111 is coupled to an output terminal of the high voltage generating unit 113 and cooperates with the high voltage generating unit 113 to regulate the output voltage HV1 by charging and discharging.

According to a preferred embodiment of the present invention, as shown in fig. 9C, the high voltage generating unit 113 includes a first inductor 1131, a first switching tube 1132 and a second switching tube 1133. The first terminal of the first inductor 1131 is connected to the primary voltage source 112 and is configured to input electrical energy from the primary voltage source 112. The first switch tube 1132 has a first end connected to the second end of the first inductor 1131, and a second end grounded, and is configured to make the primary voltage source 112 and the first inductor 1131 form a charging loop to charge the first inductor 1131 when the first switch tube is conducted. The second switch tube 1133 has a first end connected to the second end of the first inductor 1131, and a second end connected to the capacitor unit 111, and serves as an output end of the high voltage generating unit 113.

As shown in fig. 10A, in the charging phase 1, the first switch 1132 is turned on, the second switch 1133 is turned off, and the primary voltage source 112 and the first inductor 1131 form a charging loop. As shown in fig. 10B, the horizontal axis is time, the upper curve is a time-dependent curve of the current of the first inductor 1131, and the lower curve is a time-dependent curve of the output voltage HV1 of the power supply unit 11. When the first switch tube 1132 is turned on, the current of the first inductor 1131 rises linearly according to the slope of VBASE/L, where L is the inductive reactance of the first inductor 1131, and the output voltage HV1 of the power supply unit 11 maintains the initial value (equal to VBASE).

As shown in fig. 11A, the current in the charging phase 2 flows, the first switch 1132 is turned off, and since the current in the first inductor 1131 cannot change suddenly in a moment, a back electromotive force Vls is generated in the inductor Ls to maintain the passing current. At this time, the second switch tube 1133 is turned on, and after the primary voltage source 112 and the first inductor 1131 are connected in series, the capacitor unit 111 is charged with a voltage exceeding VBASE, so that the voltage of the capacitor unit 111 is raised to VBASE + VLs. As shown in fig. 11B, the horizontal axis is time, the upper curve is a time-dependent curve of the current of the first inductor 1131, and the lower curve is a time-dependent curve of the output voltage HV1 of the power supply unit 11. The first switch tube 1132 is disconnected, the second switch tube 1133 is connected, at this time, the first inductor 1131 and the capacitor unit 111 form resonance, and the voltage of the capacitor unit 111 rises from the initial voltage VBASE resonance; when the current of the first inductor 1131 decreases to 0, the second switch tube 1133 is turned off, and the capacitance of the capacitor unit is swept to the target voltage.

As shown in fig. 12A, in the current flow direction in the discharging stage 1, the first switch tube 1132 is turned off, the second switch tube 1133 is turned on, the capacitor unit 111 is used as a power supply to discharge to the first inductor 1131, and at this time, some laser or some lasers do not need to emit light or need to reduce the light emission intensity, and some energy released from the fully charged capacitor unit 111 is restored to the first inductor 1131, so as to save energy. As shown in fig. 12B, the horizontal axis is time, the upper curve is a time-dependent curve of the current of the first inductor 1131, and the lower curve is a time-dependent curve of the output voltage HV1 of the power supply unit 11. The first switch tube 1132 is disconnected, the second switch tube 1133 is connected, the capacitor unit 111 and the first inductor 1131 form resonance, and the voltage resonance of the capacitor unit 111 decreases; after the target voltage is dropped, the second switching tube 1133 is turned off.

As shown in fig. 13A, the current in the discharging phase 2 flows, the first switch 1132 is turned on, the second switch 1133 is turned off, and the primary voltage source 112 and the first inductor 1131 form a discharging loop. As shown in fig. 13B, the horizontal axis is time, the upper curve is the current of the first inductor 1131 as a function of time, the lower curve is the output voltage HV1 of the power supply unit 11 as a function of time, and the current of the first inductor decreases with a slope of-VBASE/L.

According to a preferred embodiment of the present invention, as shown in fig. 9C, the power supply unit 10 further comprises a reset switch 1134, the reset switch 1134 is connected across the primary voltage source 112 and the capacitor unit 111, and is configured to pull the output voltage HV1 back to the primary voltage VBASE. Preferably, the first switch tube 1132, the second switch tube 1133 and the reset switch tube 1134 include one or more of GaN switch and CMOS switch tube. The reset switch 1134 may be constructed by discrete devices such as MOS transistors and GaN switch transistors, or may be constructed by a gating switch.

As shown in fig. 14A, the reset switch 1134 is turned on to reset the first inductor 1131, so as to prevent the first inductor 1131 and the parasitic capacitor of the first switch 1132 from resonating again, which would affect the capacitor unit 111 and the next charging process. As shown in fig. 14B, the horizontal axis is time, the upper curve is a time-dependent curve of the current of the first inductor 1131, the lower curve is a time-dependent curve of the output voltage HV1 of the power supply unit 11, and the output voltage HV1 rapidly rises to the primary voltage VBASE.

As can be seen from the above embodiments, the fast bus power supply system provided by the present invention requires three control signals, namely, a low-side driving signal (DRVL _ HV1 shown in fig. 9C) for controlling the first switch tube 1132, a high-side driving signal (DRVH _ HV1 shown in fig. 9C) for controlling the second switch tube 1133, and a reset signal (DRVRST _ HV1 shown in fig. 9C) for controlling the reset switch tube 1134. The reasonable matching of the 3 signals can realize the adjustment time of <1us, and can meet the capability of adjusting the light intensity of the laser pixel by pixel.

According to a preferred embodiment of the present invention, the present invention further provides a control unit for controlling the power supply unit 11 as described above, wherein the high voltage generating unit 113 includes a first switching tube 1132, a second switching tube 1133 and a reset switching tube 1134, and the control unit includes: the voltage control signals are generated according to the light emitting timing of the laser, and the voltage control signals (i.e., DRVL _ HV1, DRVH _ HV1, DRVRST _ HV1 shown in fig. 9C) are respectively output to the control electrodes of the first switch tube 1132, the second switch tube 1133, and the reset switch tube 1134 to control the high voltage generating unit 113 to output an output voltage higher than the primary voltage, and control the capacitor unit 111 and the high voltage generating unit 113 to adjust the output voltage through charging and discharging cooperation.

According to a preferred embodiment of the present invention, as shown in fig. 4A, the present invention also provides a lidar transmission apparatus 10 including: a plurality of power supply units 11 as described above configured to input a primary voltage to output a high voltage, and at least two power supply units 11 output the high voltage relatively non-simultaneously, wherein the high voltage is a higher voltage with respect to the primary voltage. The laser unit 12 includes a plurality of lasers 121, wherein an anode of each of the lasers 121 is connected to an output terminal of one of the power supply units 11, such that at least two of the lasers 121 are connected to different power supply units 11. And at least one switching device 13, wherein the other end of the part of the lasers 121 which do not share the common voltage is connected to one of the switching devices 13, and the switching device 13 is configured to be capable of switching on and off a current loop formed by the corresponding power supply unit 11, the laser 121 connected with the corresponding power supply unit and the ground.

According to a preferred embodiment of the present invention, as shown in fig. 15, the present invention also provides a method 30 for controlling laser light emission using the power supply unit 11 as described above, including:

in step S301, a primary voltage is output by the primary voltage source 112;

in step S302, an output voltage higher than the primary voltage is generated by the high voltage generating unit 113;

in step S303, the output voltage is adjusted by charging and discharging the capacitor unit 111 and the high voltage generator unit 113.

According to a preferred embodiment of the present invention, wherein the high voltage generating unit 113 includes: a first inductor 1131, a first terminal of which is coupled to the primary voltage source 112, a first switch 1132, a first terminal of which is coupled to the second terminal of the first inductor 1131, a second terminal of which is grounded, and a second switch 1133, a first terminal of which is coupled to the second terminal of the first inductor 1131, a second terminal of which is coupled to the capacitor unit 111, wherein the method 30 further includes:

the first switch tube 1132 is closed, and the second switch tube 1133 is opened, so that the primary voltage source 112 and the first inductor 1131 form a charging loop, and the primary voltage source 112 charges the first inductor 1131;

when the first switch tube 1132 is opened and the second switch tube 1133 is closed, the primary voltage source 112 and the first inductor 1131 form a discharge loop, and the capacitor unit 111 is charged through the primary voltage source 112 and the first inductor 1131, so that the output voltage is higher than the primary voltage.

According to a preferred embodiment of the present invention, the method 30 further comprises:

when the first switch tube 1132 is opened and the second switch tube 1133 is closed, the capacitor unit 111 is discharged, and the first inductor 1131 inputs electric energy from the capacitor unit 111, so that the output voltage is reduced.

According to a preferred embodiment of the present invention, wherein the power supply unit 11 further comprises a reset switch 1134, the reset switch 1134 is connected across the primary voltage source 112 and the capacitor unit 111, the method 30 further comprises:

the output voltage is pulled back to the primary voltage by the reset switch 1134.

The preferred embodiment of the present invention provides a power supply unit including an LC resonant circuit, and due to the characteristics of the LC resonant circuit, the speed of charging and discharging a mounted capacitor by the power supply unit is greatly increased, and compared with the scheme of a feedback circuit used in another embodiment, the speed is increased by thousands of times.

In order to embody the effect of the HV supply circuit in the present application, fig. 9A shows a structure of a conventional HV supply circuit, where a power supply in fig. 9A outputs a high voltage HV, after sampling, the HV is compared with a reference voltage Vref to obtain an error signal, a PID controller generates a control signal u, a PWM comparator compares u with a sawtooth wave with a fixed frequency (the value is specifically related to a system using the HV circuit), and outputs a set of control pulses to control the on and off of a power switching tube, so as to maintain the output voltage relatively stable. Fig. 9B shows an operation simulation diagram using the power supply HV in fig. 9A. Comparing fig. 9B and fig. 10B, the output high voltage HV1 is 30V, and fig. 9B costs 0.9ms to 1.9ms to 1ms, but fig. 10B costs less than 0.2 μ s to 0.8 μ s to 0.6 μ s, which is a thousand-fold improvement in speed. Consequently, adopt power supply unit 11 in this application, can the fast output HV, also can carry out the switching of HV fast, and then can adjust the light intensity of laser radar's a plurality of lasers more fast relatively fast to match in the condition of external obstacle or use the scene, thereby promote the accuracy nature of point cloud detection.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power supply unit for a laser, comprising:

a primary voltage source configured to output a primary voltage;

2. The power supply unit of claim 1, wherein the high voltage generating unit comprises:

3. The power supply unit of claim 2, further comprising a reset switch connected across the primary voltage source and the capacitive unit and configured to pull an output voltage back to the primary voltage.

4. The power supply unit as claimed in claim 3, wherein the first switch tube, the second switch tube and the reset switch tube comprise one or more of GaN switch and CMOS switch tube.

5. A lidar transmitting apparatus comprising:

a plurality of power supply units according to any one of claims 1-4, configured to output voltages respectively;

and the cathodes of the partial lasers with the non-common voltage are connected to one of the switching devices, and the switching device is configured to be capable of switching on and off a current loop formed by one path of voltage, the laser connected with the switching device and the ground.

6. A control unit for controlling a power supply unit as claimed in any one of claims 1-4, wherein the high voltage generating unit comprises a first switching tube, a second switching tube and a reset switching tube, the control unit comprising:

7. A method of controlling laser emission using a power supply unit as claimed in any one of claims 1 to 4, comprising:

outputting a primary voltage by the primary voltage source;

8. The method of claim 7, wherein the high voltage generating unit comprises: a first inductor having a first terminal coupled to the primary voltage source, a first switch coupled to a second terminal of the first inductor and a second terminal coupled to ground, a second switch coupled to the second terminal of the first inductor and a second terminal coupled to the capacitor unit, the method further comprising:

9. The method of claim 7, further comprising:

10. The method as claimed in any one of claims 7-9, wherein the power supply unit further comprises a reset switch connected across the primary voltage source and the capacitive unit, the method further comprising: